The vulcanization of diene elastomers by sulphur is widely used in the rubber industry, in particular the tire industry. Use is made, in order to vulcanize diene elastomers, of a relatively complex vulcanization system comprising, in addition to the sulphur, a primary vulcanization accelerator, such as sulphenamides comprising a benzothiazole ring system, and also various secondary vulcanization accelerators or vulcanization activators, very particularly zinc derivatives, such as zinc oxide (ZnO) alone or used with fatty acids.
Such vulcanization accelerators, in order to be used in rubber compositions based on diene elastomers and on reinforcing fillers which can be used in particular for the manufacture of tires, have to induce sufficient crosslinking while retaining a delay phase (time necessary for the start of the vulcanization) which is correct, indeed even improved.
Vulcanization accelerators play a major role in the achievement of a delay phase (induction period) and it is known to a person skilled in the art that this parameter is very difficult to adjust. It is therefore particularly advantageous for a person skilled in the art to have a vulcanization accelerator which induces a lengthy delay phase which he can adjust, if desired, by the addition of additional accelerators.